1. Field of the Invention
The present invention relates to a cursor positioning control device for a cursor displayed on a display of a personal computer.
2. Description of the Related Art
There is known a cursor positioning control device for a cursor displayed on a display of a personal computer (see JP-A-H8-212008 and JP-A-H7-5989). For example, JP-A-H8-212008 describes a cursor positioning control device (pointing device) for improving usability of a user when a cursor movement operation is performed in a graphical user interface, particularly, when a cursor operation is started or stopped.
Specifically, the pointing device described in JP-A-H8-212008 includes a converter for converting a user's operation such as an operation on the converter into an input parameter. The pointing device further includes a transfer function unit connected to receive the input parameter. The transfer function unit is configured to generate a symbol movement signal indicating amplification of changes of value of the input parameter, responsive to successive input values. That is, when a user starts to operate the converter, for example, the user starts to press an isometric joystick, the input parameter changes from zero to a finite value. In the cursor movement control method employed in the pointing device, this finite value, by itself, results in a given cursor movement using the conventional transfer function.
In the meantime, JP-A-H7-5989 describes a cursor positioning control device for smoothening cursor movement between items such as menus of icons or buttons.
The cursor positioning control device described in JP-A-H8-212008 causes a “negative inertia” to be applied at acceleration and deceleration of the cursor as described above. That is, when the cursor is largely decelerated, an excessive brake is applied to decelerate the cursor. Also, when the cursor is accelerated, the “negative inertia” causes a sudden acceleration operation of the cursor. Therefore, in this cursor positioning control device, there is a problem in that when a fine operation is performed on the cursor to move the cursor, for example between adjacent icons, the negative inertia is excessively applied in concurrence with the movement of the cursor to cause the cursor to be suddenly accelerated and pass a target on which the cursor intended to be stopped. That is, there is a problem in that it is difficult to perform the fine movement operation of the cursor.
Additionally, in the cursor positioning control device described in JP-A-H8-212008, there is a case where the negative inertia is excessively applied when the cursor is stopped on the target such as an icon upon fine movement operation of the cursor as described above. As a result, there is a problem in that the cursor can not be stopped exactly on the target, and the cursor has to be returned in a direction opposite to the original movement direction and might become rather distant from the target.
On the other hand, when performing an operation of moving the cursor to the target largely distant on a display, a user intends to move the cursor as quickly as possible because the starting point of the cursor is distant from the target (end point). Accordingly, the speed of the cursor largely increases near the target.
Generally, a user visually estimates a timing when the movement of the cursor is stopped, and intends to stop the cursor by reflecting the motion of a mouse by the hand or the motion of a pointing stick by the finger. However, since a thinking process needs to be performed at the brain between the visual recognition and the stop operation, a time lag occurs between the visual recognition and the stop operation. As a result, even though the motion of the mouse or the pointing stick is stopped by the hand or finger at the moment when the user intends to stop the cursor based on the visual sense, the cursor might pass the target. Accordingly, it becomes necessary to adjust the position of the cursor on the target by returning the cursor in a direction opposite to the original movement direction of the cursor.
Particularly, when a user who is used to moving a cursor with the hand on a mouse connected to a desktop computer or a notebook computer replaces the computer with a notebook computer including a pointing stick to move a cursor, there occur many cases similarly to the above because the user is unfamiliar with the pointing stick that the user manipulates with the finger. Also, when even a user familiar with the operation of the pointing stick uses the notebook computer during riding in airplane or train that is always vibrated, the operation efficiency of the pointing stick may be largely reduced.
In the meantime, the cursor positioning control device described in JP-A-H7-5989 reduces the amount of operation of the pointing device such as a mouse, in the cursor movement between items such as menus of icons or buttons. Accordingly, this device can facilitate a fine operation such as pointing of icons, buttons, and menus and can smoothen the cursor movement in response to the operation of the pointing device regardless of the position of the cursor on the display. However, in the object of the invention described in JP-A-H7-5989, it is not described to perform appropriate positioning control by preventing the passing or returning of the cursor with respect to the target. That is, an object of the present invention is different from that of JP-A-H7-5989.